Testing sample biological specimens is commonly done to, for example, check for the presence of an item of interest, which item may be or include all or portions of a specific region of DNA, RNA, fragments, complements, peptides, polypeptides, enzymes, prions, proteins, messenger RNA, transfer RNA, mitochondrial RNA or DNA, antibodies, antigens, allergens, parts of biological entities such as cells, virons or the like, surface proteins, functional equivalents of the above, etc. Specimens such as a patient's body fluids (e.g., serum, whole blood, urine, swabs, plasma, cerebra-spinal fluid, lymph fluids, tissue solids) can be analyzed using a number of different tests to provide information about a patient's health.
In such testing, it is imperative that the specimens be handled in a manner which prevents contaminants from being introduced to the specimens, whether from the outside environment or between specimens. Obviously, where the HIV virus from one specimen is inadvertently allowed to contaminate the specimen of a different patient, the resulting false positive test result could potentially have catastrophic psychological effect on the patent, even should subsequent testing later discover the error. Moreover, since such testing is highly sensitive, even the smallest amounts of contamination can cause erroneous test results. In such sophisticated testing, it is also imperative that the various reagents which may be used in the testing be properly handled as well, not only to avoid contaminants but also to ensure that the proper reagent in proper quantities is used at appropriate times.
Commonly, such testing is accomplished using automated devices which handle multiple specimens and fluids (typically, reagents). For example, U.S. Pat. No. 6,588,625 B2 and U.S. Application Publication No. 2004/0005714 A1 (the disclosures of which are hereby incorporated by reference) variously disclose systems for handling fluids and specimens of this type.
Such automated devices often use sets of pipettes to move various fluids between their original containers (usually receptacles such as open topped tubes) and containers in which the specimens are to be processed. For example, a specimen may be contained in a tube loaded in a rack on the device, and a head carrying a pipette will through programmed motion move the pipettes into that tube, where a vacuum will be applied to extract a selected amount of the specimen from the tube into the pipette. The head will then retract the pipette from the tube and move over to another tube or reaction vessel located at a processing station, depositing the extracted amount of the specimen from the pipette into the reaction vessel. A similar process may be followed to acquire an appropriate reagent (depending upon the desired test) from a reagent supply.
At the processing station of such automated devices, the specimens are variously handled according to the purpose of the testing (e.g., incubated, prepared, lysed, eluted, analyzed, read, etc.). For example, the specimens may be prepared for analyzing, as for example by separating DNA or RNA from the specimen. The specimens may also or alternatively be analyzed. Commonly, such processes involve the addition of various fluids (typically reagents) to the specimen in each tube. For example, in a first step, a reagent may be added to each of the tubes to wash the specimens, and second and third (and more) reagents may be added to the specimens in the course of carrying out other processes to, for example, unbind and/or separate the DNA or RNA of interest allow so that it may be extracted from the specimen in each tube for subsequent testing. Similar processes, in which the same or different reagents are added to the tubes, may also occur after the specimen has been prepared as a part of the analyzing of the prepared specimens.
The handling of the reagents and other fluids can, with such automated devices, be problematic. Though the reagents can be automatically moved from receptacles to the specimen containing tubes in the processing station by use of the head and pipettes such as noted, it is in the first instance necessary to load the appropriate reagent into the appropriate receptacle on the device in order to ensure that the head and pipettes are adding the appropriate reagent to the appropriate specimen containing tube at the appropriate time in the process.
Heretofore, loading the appropriate reagent into the appropriate receptacle has been accomplished in several different ways. In one such procedure, the individual who is controlling the device manually measures and adds the reagents to receptacles, and then places those receptacles on the device. In another such procedure, the loading of reagents is automatically accomplished by the device itself, which uses some transfer apparatus (such as a head and pipette(s) as previously described) to move the reagents from bulk supplies of the reagents provided with the device. However, either of the above procedures can be problematic. For example, manually adding the reagents can introduce human error, such as mounting the reagent receptacle incorrectly on the device. Moreover, even if the reagents are correctly loaded in the correct amounts, they may be loaded at the wrong location on the device so that when the head and pipettes automatically draw a reagent for use at a certain step of the processing, it may well be the wrong reagent, or there could be no reagent of any kind where the head and pipettes go to extract it.
The Architect® i2000 systems of Abbott Laboratories of Abbott Park, Ill. is a high throughput analyzer providing automated operation in which the operator may be freed from interacting with the analyzer for long periods of time. With that device, bulk supplies of reagents can be manually loaded onto a refrigerated carousel, with the analyzer then automatically obtaining the desired samples and reagents for the processing station at which testing procedures are accomplished. The containers for the reagents and samples are barcoded for automatic tracking on the system. Each reagent container can contain sufficient reagents for many tests so that, depending upon usage and the types of tests most commonly performed, some reagent containers can be maintained on the carousel for long periods of time. Particularly for reagents which are made with suspended microparticles, consistent use and dosages may be negatively impacted due to settling of the microparticles over time.
The present invention is directed to improving upon the reagent and sample handling devices of the prior art testing systems such as described above.